Feed chucks



FEED CHUCKS Original Filed Aug. 25, 1954 FEED CHUCKS Originalapplication August 25, 1954, Serial No. 452,052.

Divided and this application September 8, 1955, Serial No. 533,315

7 Claims. (Cl. 279-43) This invention relates to improvements in feedchucks or feed fingers of the kind commonlyused for advancing the workin automatic screw machines, lathes, or the like. More particularly thisinvention relates to feed chucks of the type commonly referred to assquirrel cage feed chucks.

Feed chucks of this type have generally been made by providing a tubularmember with longitudinally extending slots terminating in spacedrelation to the ends of the member and having the metal between theslots bent inwardly toward the axis of the tubular member into positionsto engage the stock tobe fed. These inwardly projecting parts when wornby contact with the stock so that they failed to properly grip thestock, were forced inwardly to a greater extent, generally by hammerblows, which involved the difiiculty of forcing each of the inwardlyextending parts toward the axis to the same extent, as is necessary forthe efiicient operation of the feed chuck.

One of the objects of this invention is to provide a feed chuck of thistype in which the inwardly extending parts are in the form of separatesprings removably secured to the feed collet so that they can be removedand replaced when worn or replaced by other springs formed to cooperatewith stock of different diameter or cross sectional shape. Anotherobject is to provide a feed chuck of this type in which the inwardlyextending springs may be bowed to varying degrees by means of pressureapplied to the ends of the springs. It is also an object of thisinvention to provide a feed chuck in which the inwardly extendingsprings are all moved simultaneously toward and from the axis of thefeed chuck so that all of the springs will exert substantially the samepressure on the stock. A further object is to provide a feed chuck ofthis type with a nut or threaded sleeve formed to engage one end of eachspring member for the purpose of bowing the springs into the feed chuckto a greater or less extent and in which the springs servesimultaneously for the purpose of locking the sleeve or nut in itsadjusted positions.

Other objects and advantages will be apparent from the followingdescription of one embodiment of the invention and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

In the accompanying drawings:

Fig. l is a side view of a feed chuck or finger embodying this inventionshowing the same holding stock in the form of a rod.

Fig. 2 is a fragmentary central sectional elevation thereof, on line 22,Fig. 3.

Fig. 3 is a fragmentary side view of the discharge end of the feedchuck.

Fig. 4 is an end view thereof.

Fig. 5 is a transverse sectional elevation thereof, on line 5--5, Fig.3.

Fig. 6 is a similar view thereof, showing the feed chuck adapted foroperation on stock of hexagonal cross sectional shape.

ited States Patent 0 F 2,786,687 Patented Mar. 26, 1957 Fig. 7 is asimilar sectional view showing a feed chuck adapted for operation onstock of square cross section.

In the embodiment of this invention shown in the drawings by way ofexample, 8 represents the tubular body member of a feed chuck. This bodymember is provided at the receiving end thereof with a threaded part 9which is formed for threaded engagement with the usual feed tube whichis advanced in the direction of its axis whenever the stock is to be fedforwardly. 10

represents a piece of stock with which my improved feed chuck maycooperate.

The body member 8 is provided at intervals about the periphery of thesame with slots or cut-out portions 11 arranged intermediate of the endsof the body member. Any desired number of these slots may be provided,three being shown in the construction illustrated. Beyond the outer endsof these slots, the body member is provided at its discharge end with apart 12 of reduced diam eter which is threaded on the exterior surfacethereof.

The stock to be fed by the feed chuck is engaged by means of springsremovably mounted on the body member and preferably arranged in theslots 11. These springs are bowed inwardly so that the middle portions14 thereof extend toward the axis of the body into position to engagethe stock. The inner end portions 15 of the springs may be secured infixed relation to the body member in any suitable or desired manner, andin the construction shown for this purpose, slots or recesses 16 areformed in the body member at the inner ends of the slots into which theextremities of the end portions 15 may enter.

The other or outer ends 17 of the springs lie in longi tudinallyextending grooves formed in the reduced end portions 12 of the body 8.The extremities of the end portion 17 extend to a limited extent beyondthis end of the body and the grooves in which these end portions 17 lieare of such depth as to be below the threads formed in the reduced endportion 12, so that these threads will be free to engage withcorresponding internal threads formed on a nut or sleeve 20 so that thisnut or sleeve may be freely threaded on this threaded end of the bodymember without interference with the end portions 17 of the springs.

The nut or sleeve 20 is formed to engage the outer ends of the springsand for this purpose in the construction shown, the nut or sleeve has aninwardly extending annular flange or bead 21 which forms a shoulder toengage the outer extremities of the end portions17 of the springs. thenut or sleeve, so that the threaded part of the sleeve overlies theseends of the springs and thus confines them to the grooves. It will thusbe seen that when the sleeve 20 is turned so as to move to the left inFigs. 1 to 3, the flange 21 of the sleeve will exert inward pressureagainst the end portions 17 of the springs. This pressure will tend tobow the middle portion 14 thereof inwardly toward the axis of the bodymember, thus making it possible for the springs to either grip the stockmore firmly or to move the parts 14 of the springs nearer to the axis ofthe body member to cooperate with stock of somewhat smaller sizes. Byturning the sleeve 20 so as to move the same outwardly from the end ofthe body member, it will, of course, also be obvious that the stockengaging springs will have less pressure exerted on the same with theresult that less press will be exerted on the stock, or if desired, thefeed chuck may cooperate with stock of slightly larger diameter.

After the sleeve 20 has adjusted the springs for the stock with which itis to cooperate, so that the springs will grip the stock with thedesired pressure, the sleeve will also be frictionally held in itsadjusted position because of contact with the outer extremities of theends 17 of the springs. Since these ends of the springs exert Thisflange is arranged near the outer end of,

a yielding pressure against the sleeve, they will resist turning of thesleeve due to shocks or jars to which the feed chuck is subjected. Othermeans may be provided to hold the sleeve against turning.

The springs can readily be removed from the tubular body 8 by unscrewingthe sleeve from the end thereof, whereupon the springs may be lifted outof the grooves in the threaded end 12 ofv the body member and alsowithdrawn from the recesses 16. These springs can then be readilyreplaced by others when worn out or when it is desired to operate onstock of different size or shape. For example in Figs. 1 to 5, I haveshown the springs with the stock contacting portions 14 thereof ofarc-shaped cross section to cooperate with a round bar 10. If it isdesired to operate upon hexagonal stock 24, as shown in Fig. 6, thesprings may be provided with list intermediate portions formed to engagewith three of the fiat. surfaces of hexagonal stock. When the feed chuckis to be used for feeding stock of square cross section, the body membercan be provided with two slots as shown in. Fig. 7, to receive twosprings 31 positioned to act on opposite faces of a square bar, or withfour slots for receiving foursprings.

The feed chuck described has the advantage that tension of the springscan be very easily adjusted by merely turning the nut or sleeve 20.

The feed chuck shown has the further advantage that it is inexpensive toproduce and to maintain in operating condition, since the springs arerelatively inexpensive to produce. In cases where wear is a problem, thesprings may be plated with hard and wear-resistant materials.

By arranging the springs in slots as shown, they are held againstrotation relatively to the body member 8, so that the work operated uponwill not transmit rotative force to the adjusting sleeve 20, so thatturning of this sleeve, which would result in varying the tension of thesprings, will not result. Consequently, the spring pressure will remainsubstantially uniform unless manually changed. Furthermore, by arrangingthe springs in the slots as shown, the feed chuck can operate on work oflarger diameter than in the case of feed chucks in which no slots areprovided in the body member.

The springs 14 can be readily replaced so that the tubular body memberof the feed chuck may be used repeatedly with different springs. Thelife of the body member is, consequently, very long, since it is notsubject to any substantial amount of wear.

This application is a substitute for abandoned application 452,052,filed August 25, 1954.

It will be understood that various changes in the details, materials,and arrangements of parts which have been herein described andillustrated in order to explain the nature of the invention, may be madeby those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.

I claim as my invention:

1. A feed chuck including a tubular body member having a plurality oflongitudinally extending slots arranged at intervals about the peripherythereof intermediate of the ends of said body member, a spring in eachof said slots having one end fixed in an end of its slot and having itsmiddle portion bowed into said body member, and means cooperating withsaid body member and with the other ends of said springs for furtherbowing said springs inwardly with reference to said body member toengage with stock within said body member.

2. A feed chuck according to claim 1, in which said body member hasrecesses at the ends of said slots in which the fixed ends of saidsprings seat.

3. A feed chuck according to claim 1, in which said means cooperatingwith said other ends of said springs is a sleeve having a threadedengagement with said body member and engaging said other ends of saidsprings.

4. A feed chuck according to claim 1, in which said means cooperatingwith said other ends of said springs is a sleeve having a threadedengagement with said body member and having an inwardly extending flangewhich engages said other ends of said springs.

5. A feed chuck according to claim 1, and in which said middle portionsof said springs are of a cross sectional shape correspondingapproximately to parts of the cross sectional shape of the stock to befed.

6. A feed chuck including a tubular body member having a plurality oflongitudinally extending slots arranged at intervals about the peripherythereof, a spring for each of said slots and having the middle portionthereof bowed to extend into said body member, said body member havingrecesses at the ends of said slots into which one end of each springextends, said body member having the leading end thereof threaded,grooves in said threaded portion in which the other ends of said springslie, and beyond which they extend, said grooves being of suficieut depthso that said last mentioned ends of said springs lie below the threadsof said threaded end, and a threaded sleeve engaging said threaded endand having a part engaging said other ends of said springs to vary theextent to which said springs are bowed.

7. A feed chuck according to claim 6, in which said sleeve has a partoverlying said other ends of said springs to retain them in said groovesand an inwardly extending flange engaging said other ends of saidsprings.

No references cited.

